Portable optical touch system

ABSTRACT

There is provided a portable optical touch system including a first image sensing module, a second image sensing module, a connecting device, a communication interface and a processing circuit. The two image sensing modules have partially overlapped field of views and the partially overlapped field of views is for defining a touch region. The connecting device is configured to adjust or fix a distance between the first and second image sensing modules. When an object is in the touch region, the processing circuit calculates a position of the object according to images of the object acquired by the two image sensing modules and outputs information of the position of the object through the communication interface.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan PatentApplication Serial Number 099117670, filed on Jun. 01, 2010, the fulldisclosure of which is incorporated herein by reference.

This application is a continuation in part patent application of U.S.application No. 13/110,844 filed on May 18, 2011, the entire contents ofwhich are hereby incorporated by reference for which priority is claimedunder 35 U.S.C. §120.

BACKGROUND

1. Field of the Invention

This invention generally relates to the field of touch controltechnology and, more particularly, to a portable optical touch system, aportable optical touch device and a method for detecting a position ofat least one object.

2. Description of the Related Art

FIG. 1 shows a solid diagram of a conventional optical touch system.Please refer to FIG. 1, an optical touch system 100 includes a panel104, image sensing modules 106 and 108, a processing circuit 110, areflecting element 112, a reflecting element 114 and a reflectingelement 116. In addition, a quadrilateral area referred by a numericalreference 118 shown in FIG. 1 is served as a touch region of the opticaltouch system 100, and the image sensing modules 106 and 108 arerespectively disposed at two different corners of the touch region 118such that field of views of the two image sensing modules 106 and 108can respectively cover the touch region 118. In this embodiment, a shapeof the touch region 118 is a quadrilateral, and preferably a rectangle.A numerical reference 102 shown in FIG. 1 refers to an object.

In the components of the optical touch system 100, the reflectingelement 112, reflecting element 114 and reflecting element 116 are madeof retro-reflective material and configured to reflect incident light(e.g. IR light) to the touch region 118. The image sensing modules 106and 108 are configured to acquire images looking across the touch region118. The processing circuit 110 is configured to receive the imagesacquired by the image sensing modules 106 and 108, and calculatecoordinates of the object 102 relative to the touch region 118 accordingto the images acquired by the image sensing modules 106 and 108.

FIG. 2 shows an operation diagram of the single point control of theoptical touch system shown in FIG. 1. In FIG. 2, numerical referencesidentical to those shown in FIG. 1 refer to the same components. Asshown in FIG. 2, the image sensing module 106 detects the object 102following a route 202 while the image sensing module 108 detects theobject 102 following a route 204. Accordingly, as long as the processingcircuit 110 is able to obtain linear equations of the routes 202, 204and further to calculate a cross point thereof, a coordinate of theobject 102 can then be obtained.

The method of how the two linear equations of the routes 202 and 204 areobtained by the optical touch system 100 will be illustratedhereinafter. But the structure of the image sensing modules 106 and 108will be illustrated first.

Taking the optical sensing module 106 as an example, its structure isshown in FIG. 3. FIG. 3 shows a block diagram of the image sensingmodule 106. Please refer to FIG. 3, the image sensing module 106includes an IR emitter 302, an optical lens set 304, an IR filter 306allowing only IR light to pass through, and an image sensor 308; whereinthe IR emitter 302 is configured to emit IR light to illuminate thetouch region 118, reflecting element 112, reflecting element 114 andreflecting element 116; and the image sensor 308 acquires images insideand looking across the touch region 118 sequentially through the IRfilter 306 and the optical lens set 304, and transmits the acquiredimages to the processing circuit 110. When the object 102 is inside thetouch region 118, the image sensing module 106 is able to acquire imagescontaining the image of the object 102 as shown in FIG. 4.

FIG. 4 shows a schematic diagram of an image acquired by the imagesensing module 106. In FIG. 4, a white region referred by a numericalreference 402 is a bright zone which has a higher brightness in theacquired image and is formed by sensing the IR light emitted from the IRemitter 302 and the IR light reflected by the reflecting elements 114and 116, and the bright zone 402 is served as a main sense region of thesystem. A numerical reference 404 refers to a dark zone formed by theobject 102 from blocking the bright zone 402.

From FIGS. 2 and 4, it is known that as long as the processing circuit110 is able to obtain an angle a (i.e. an included angle between theroute 202 and an upper side of the touch region 118) and a gravitycenter (or a center) of the dark zone 404, the linear equation of theroute 202 can then be calculated. Similarly, the processing circuit 110is able to calculate the linear equation of the route 204 by usingsimilar method. A coordinate of the object 102 is the cross point of theroutes 202 and 204.

The optical touch system shown in FIG. 1 can perform the functions of auser input interface, e.g. a mouse, a keyboard or a touchpad for acomputer system such that a user may perform input operation directlywith his or her finger. However, since the optical touch system 100 hasto adopt the physical panel 104, reflecting element 112, reflectingelement 114 and reflecting element 116 for operation, the operationalenvironment is significantly limited. Furthermore, the physical panel104, reflecting element 112, reflecting element 114 and reflectingelement 116 are not cheap such that this kind of optical touch systemhas a high price. In addition, as the panel 104 has a considerablevolume and the reflecting element 112, reflecting element 114 andreflecting element 116 have considerable lengths, the size of theoptical touch system 100 can not be further reduced to be carriedeasily.

Accordingly, problems need to be solved in a modern optical touch system100 include the using environment, cost, size and portability.

SUMMARY

It is an object of the present invention to provide a portable opticaltouch system.

It is another object of the present invention to provide a portableoptical touch device.

It is a further object of the present invention to provide a method fordetecting a position of at least one object that may be adapted to theportable optical touch system and device mentioned above.

The present invention provides a portable optical touch system includinga first image sensing module, a second image sensing module, alength-adjustable connecting device, a communication interface and aprocessing circuit. A field of view of the first image sensing moduleand a field of view of the second image sensing module are partiallyoverlapped and the partially overlapped field of views is for defining atouch region. The length-adjustable connecting device is configured toadjust a distance between the first image sensing module and the secondimage sensing module. The processing circuit is for calculating aposition of an object in the touch region according to images of theobject acquired by the first image sensing module and the second imagesensing module, and for outputting information of the position throughthe communication interface.

The present invention further provides a portable optical touch systemincluding a first image sensing module, a second image sensing module, aconnecting device, a communication interface and a processing circuit. Afield of view of the first image sensing module and a field of view ofthe second image sensing module are partially overlapped and thepartially overlapped field of views is for defining a touch region. Theconnecting device connects the first image sensing module and the secondimage sensing module, wherein a distance between the first image sensingmodule and the second image sensing module is a predetermined length.The processing circuit is for calculating a position of an object in thetouch region according to images of the object acquired by the firstimage sensing module and the second image sensing module, and foroutputting information of the position through the communicationinterface.

The present invention further provides a portable optical touch devicefor detecting a position of at least one object, and the portableoptical touch device includes a first image sensing module, a secondimage sensing module, at least one IR emitter, a processing circuit anda display screen. The first image sensing module further includes afirst image sensor, a first IR filter and a first optical lens set. Thesecond image sensing module further includes a second image sensor, asecond IR filter and a second optical lens set. The at least one IRemitter is disposed in the vicinity of the first image sensing moduleand/or the second image sensing module. A field of view of the firstimage sensing module and a field of view of the second image sensingmodule are partially overlapped and the partially overlapped field ofviews is for defining a touch region. The at least one IR emitter isconfigured to emit IR light to illuminate the object in the touchregion. The first image sensing module and the second image sensingmodule acquire images of the object respectively through the first IRfilter and the second IR filter. The first optical lens set and thesecond optical lens set are respectively disposed in front of the firstimage sensor and the second image sensor for broadening a field of viewof the associated image sensor to at least 90 degrees. The processingcircuit is for calculating and outputting information of the position ofthe object according to the images of the object acquired by the firstand second image sensing modules. The display screen is configured todisplay and correlate with the position of the object outputted by theprocessing circuit.

The present invention further provides a portable optical touch devicefor detecting a position of at least one object, and the portableoptical touch device includes a first image sensing module, a secondimage sensing module, at least one laser emitting device, a thirdoptical lens set, a processing circuit and a display screen. The firstimage sensing module further includes a first image sensor and a firstoptical lens set. The second image sensing module further includes asecond image sensor and a second optical lens set. The at least onelaser emitting device is disposed nearby the first image sensing moduleand/or the second image sensing module. The third optical lens set isdisposed in front of the at least one laser emitting device. A field ofview of the first image sensing module and a field of view of the secondimage sensing module are partially overlapped and the partiallyoverlapped field of views is for defining a touch region. The at leastone laser emitting device is configured to emit a point laser light tobe converted to a linear laser light through the third optical lens setto illuminate the object in the touch region. The first image sensor andthe second image sensor acquire images of the object respectivelythrough the first optical lens set and the second optical lens set. Thefirst optical lens set and the second optical lens set are respectivelyconfigured to broaden a field of view of the associated image sensor toat least 90 degrees. The processing circuit is for calculating andoutputting information of the position of the object according to theimages of the object acquired by the first and second image sensingmodules. The display screen is configured to display and correlate withthe position of the object outputted by the processing circuit.

The present invention further provides a method for detecting a positionof at least one object that may be adapted to a portable optical touchsystem including a first image sensing module, a second image sensingmodule, a connecting device, a processing circuit and a communicationinterface, wherein a field of view of the first image sensing module anda field of view of the second image sensing module are partiallyoverlapped and the partially overlapped field of views is for defining atouch region, and the connecting device is configured to adjust or fix adistance between the first and second image sensing modules. The methodincludes the steps of: acquiring images of the object in the touchregion by using the first and second image sensing modules; calculatingthe position of the object by using the processing circuit according tothe images of the object acquired by the first and second image sensingmodules; and outputting information of the position of the objectthrough the communication interface.

The present invention mainly adopts two image sensing modules and aprocessing circuit to construct a portable optical touch system. In anactual design, the two image sensing modules have partially overlappedfield of views and the partially overlapped field of views is fordefining a touch region. In this manner, when there is an object insidethe touch region, the processing circuit may calculate a position of theobject according to images of the object acquired by the two imagesensing modules. In a further design, the two image sensing modules mayemit IR light or laser light to illuminate the object so as to acquirethe images of the object reflecting the IR light or the laser lightwhereby the processing circuit is able to calculate the position of theobject according to these acquired images. In a further design, the IRlight or the laser light may be emitted by a component disposed outsidethe image sensing modules to illuminate the object in the touch region.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages, and novel features of the present inventionwill become more apparent from the following detailed description whentaken in conjunction with the accompanying drawings.

FIG. 1 shows a solid diagram of a conventional optical touch system.

FIG. 2 shows an operation diagram of the single point control of theoptical touch system shown in FIG. 1.

FIG. 3 shows a block diagram of the image sensing module.

FIG. 4 shows a schematic diagram of an image acquired by the imagesensing module.

FIG. 5 shows a solid diagram of the portable optical touch systemaccording to an embodiment of the present invention.

FIG. 6 shows another solid diagram of the portable optical touch systemshown in FIG. 5.

FIG. 7 shows a top perspective view of the portable optical touch systemshown in FIG. 5.

FIG. 8 shows a side perspective view of the image sensing module.

FIG. 9 shows an operation diagram of single point control of theportable optical touch system shown in FIG. 7.

FIG. 10 shows a schematic diagram of the processing circuit receivingand post-processing image data from two image sensors.

FIG. 11 shows a schematic diagram of corresponding angles relative toobject positions in an image acquired by the image sensor.

FIG. 12 shows another arrangement of internal components of the imagesensing module.

FIG. 13 shows a calculation method of the farthest field of view.

FIG. 14 shows a modified portable optical touch system.

FIG. 15 shows a function pattern of the mouse in the touch regiondefined by the processing circuit.

FIG. 16 shows a schematic diagram of the portable optical touch systemof the present invention being disposed in a slot of an electronicdevice.

FIG. 17 shows a flow chart of the method for detecting an objectposition according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT First Embodiment

FIG. 5 shows a solid diagram of the portable optical touch systemaccording to an embodiment of the present invention; FIG. 6 showsanother solid diagram of the portable optical touch system shown in FIG.5; and FIG. 7 shows a top perspective view of the portable optical touchsystem shown in FIG. 5. Please first refer to FIGS. 5 and 7, theportable optical touch system 500 includes an image sensing module 510,an image sensing module 530, a length-adjustable connecting device 550,a communication interface 560 and a processing circuit 570. The imagesensing module 510 has a housing 5101 which has a transparent part 5102.The image sensing module 530 has a housing 5301 which has a transparentpart 5302. Two terminals of the length-adjustable connecting device 550respectively connect to the housings 5101 and 5301, and thelength-adjustable connecting device 550 is configured to adjust adistance between the image sensing modules 510 and 530.

The length-adjustable connecting device 550 may adopt a multiplesegmental length-adjustable rod structure or slide rail structure torealize length adjustment function, but the length-adjustable connectingdevice 550 of the present invention is not limited thereto. In addition,in this embodiment the communication interface 560 may be a wiredcommunication interface, such as a universal serial bus (USB) interface,but not limited thereto. A specification of the USB interface may be USB1.0, USB 1.1, USB 2.0 or USB 3.0. Please refer to FIG. 6, in whichnumerical references identical to those shown in FIG. 5 refer to thesame components. FIG. 6 mainly shows that a length of thelength-adjustable connecting device 550 may be shortened to an extentthat the image sensing modules 510 and 530 are in contact with eachother for easy to carry.

Please refer to FIG. 7, in which numerical references identical to thoseshown in FIG. 5 refer to the same components. A numerical reference 502represents an object, such as the finger of a user or a pen-like object.In this embodiment, in addition to the housing 5101, the image sensingmodule 510 further includes an image sensor 512, an infrared (IR) filter514 allowing only IR light to pass through, an optical lens set 516composed of optical lenses 5161 and 5162, an IR emitter 518 and anoptical lens 520; wherein the image sensor 512 may be a charge-coupleddevice (CCD) or a CMOS image sensor. The type of the image sensor 512may be an array type or a linear type image sensor. In addition, in thisembodiment a field of view of the image sensor 512 may be about 30 to 45degrees and the image sensing module 510 adopts the optical lens set 516to broaden the field of view of the image sensor 512 to at least 90degrees such that a sensing area of the image sensing module 510 maycover at least the area within an included angle between dotted lines582 and 584. In the optical lens set 516, each optical lens may increaseat least 30 degrees field of view of the image sensor 512.

As for the IR emitter 518, the IR light emitted thereby illuminates theobject 502 and an area covered within the included angle between thedotted lines 582 and 584 sequentially through the optical lens 520 andtransparent part 5102 such that the image sensor 512 may acquire theimage of the object 502 reflecting the IR light sequentially through theIR filter 514, optical lens set 516 and transparent part 5102. That is,a shape and a size of the transparent part 5102 have to be designed toallow the image sensor 512 to be able to acquire the image of the areacovered within the included angle between the dotted lines 582 and 584,and the transparent part 5102 should not block the propagation of the IRlight emitted from the IR emitter 518 and passing through the opticallens 520 and should allow the IR light to illuminate all places insidethe area covered within the included angle mentioned above.

Similarly, in addition to the housing 5301, the image sensing module 530further includes an image sensor 532, an IR filter 534 allowing only IRlight to pass through, an optical lens set 536 composed of opticallenses 5361 and 5362, an IR emitter 538 and an optical lens 540. In thisembodiment, a field of view of the image sensor 532 may be about 30 to45 degrees and the image sensing module 530 adopts the optical lens set536 to broaden the field of view of the image sensor 532 to at least 90degrees such that a sensing area of the image sensing module 530 maycover at least the area within an included angle between dotted lines582 and 586. In the optical lens set 536, each optical lens may increaseat least 30 degrees field of view of the image sensor 532.

As for the IR emitter 538, the IR light emitted thereby illuminates theobject 502 and an area covered within the included angle between thedotted lines 582 and 586 sequentially through the optical lens 540 andtransparent part 5302 such that the image sensor 532 may acquire theimage of the object 502 reflecting the IR light sequentially through theIR filter 534, optical lens set 536 and transparent part 5302. That is,a shape and a size of the transparent part 5302 have to be designed toallow the image sensor 532 to be able to acquire the image of the areacovered within the included angle between the dotted lines 582 and 586,and the transparent part 5302 should not block the propagation of the IRlight emitted from the IR emitter 538 and passing through the opticallens 540 and should allow the IR light to illuminate all places insidethe area covered within the included angle mentioned above. In otherembodiment, the IR emitter 518 may be disposed outside the image sensingmodule 510 and in the vicinity of the image sensing module 510 toilluminate the object 502 and the touch region 590; the IR emitter 538may be disposed outside the image sensing module 530 and in the vicinityof the image sensing module 530 to illuminate the object 502 and thetouch region 590. In addition, with proper design, only one of the IRemitters 518 and 538 is implemented and disposed in the vicinity of theimage sensing module 510 or the image sensing module 530 to illuminatethe object 502 and the touch region 590.

It is known from the above description that the included angle betweenthe dotted lines 582 and 584 is about 90 degrees and that between thedotted lines 582 and 586 is also about 90 degrees. Therefore, a field ofview of the image sensing module 510 and a field of view of the imagesensing module 530 are partially overlapped and the partially overlappedfield of views is used to define a touch region 590. In addition, it isknown from FIG. 7 and the above description that the image sensor 512 isdisposed substantially at an intersection of the dotted lines 582 and584 while the image sensor 532 is disposed substantially at anintersection of the dotted lines 582 and 586. That is, the image sensors512 and 532 are respectively disposed at two different corners of thetouch region 590.

FIG. 8 shows a side perspective view of the image sensing module 510. InFIG. 8, numerical references identical to those shown in FIGS. 5 and 7refer to the same components. A numerical reference 802 refers to anactual working surface. As shown in FIG. 8, there is a firstpredetermined included angle θ1 between an image sensing surface 512A ofthe image sensor 512 and a bottom surface 5101A of the housing 5101, andthe first predetermined included angle θ1 is 90 degrees in thisembodiment. In addition, the IR filter 514, optical lens set 516, IRemitter 518 (not shown in FIG. 8) and optical lens 520 (not shown inFIG. 8) are disposed in association with the first predeterminedincluded angle θ1. Since the first predetermined included angle θ1 is 90degrees, a theoretical field of view of the image sensor 512 isindefinite, i.e. a theoretical depth of field of the image acquired bythe image sensor 512 is indefinite. However, an actual depth of fieldmay be determined by the environment and physical limitations of thecomponents themselves. In addition, if the IR light emitted by the IRemitter 518 covers the whole field of view of the image sensor 512, theobject 502 may reflect the IR light for being detected by the imagesensor 512 after entering the illuminated region of the IR light.

Similarly, the image sensor 532, IR filter 534, optical lens set 536, IRemitter 538 and optical lens 540 in the image sensing module 530 mayalso be arranged similar to FIG. 8. Further, there is a secondpredetermined included angle between an image sensing surface of theimage sensor 532 and a bottom surface of the housing 5301, and thesecond predetermined included angle is 90 degrees in this embodiment.

Please refer to FIG. 7 again, in this embodiment the processing circuit570 is disposed inside the housing 5101 of the image sensing module 510and electrically coupled to the communication interface 560, imagesensor 512 and image sensor 532. Therefore, when the object 502 is inthe touch region 590, the image sensors 512 and 532 are able to acquireimages of the object 502 reflecting the IR light, and then directlytransmit acquired image data to the processing circuit 570. Or the imagesensors 512 and 532 may preprocess the acquired image data to retrievethe character information of image (e.g. the parameter of area, lengthwidth ratio, boundary, color and/or brightness of the object image) andthen transmit preprocessed results to the processing circuit 570 so asto reduce the loading of the processing circuit 570. The processingcircuit 570 then calculates a position of the object 502 according tothese image data or the character information of image. After obtainingthe position of the object 502, the processing circuit 570 transmitsinformation of the position of the object through the communicationinterface 560 to an electronic device, e.g. a notebook, to allow theelectronic device to perform further operations according to theinformation of the position of the object. A method of obtaining theposition of the object will be further illustrated hereinafter.

FIG. 9 shows an operation diagram of the single point control of theportable optical touch system shown in FIG. 7. In FIG. 9, numericalreferences identical to those shown in FIG. 7 refer to the samecomponents. In FIG. 9, a point A denotes the disposed position of theimage sensor 512 and a point B denotes the disposed position of theimage sensor 532. As shown in FIG. 9, when the object 502 is in thetouch region 590, the image sensor 512 may detect the object 502following the route 902 and the image sensor 532 may detect the object502 following the route 904. Therefore, as long as the processingcircuit 570 is able to obtain linear equations of the routes 902 and 904respectively according to the images acquired by the image sensors 512and 532, a cross point of these two routes may further be calculated soas to obtain the position of the object 502. A method of how theprocessing circuit 570 can obtain the linear equations of these tworoutes according to the images acquired by the two image sensors 512 and532 will be further illustrated hereinafter.

FIG. 10 shows a schematic diagram of the processing circuit 570receiving and post-processing the image data from the two image sensors512 and 532. In FIG. 10, a numerical reference 1010 refers to an imageacquired by the image sensor 512; a numerical reference 1012 refers to abright zone in the image 1010 formed by sensing the IR light reflectedby the object 502 (i.e. the object image); numerical references 1014 and1016 respectively refer to the left edge and the right edge of thebright zone 1012; and a numerical reference 1018 refers to a center, agravity center or a mean (or an average) of the bright zone 1012.Numerical references 1014, 1016 and 1018 refer to the characterinformation of the object 502 in the image 1010 herein.

Similarly, a numerical reference 1020 refers to an image acquired by theimage sensor 532; a numerical reference 1022 refers to a bright zone inthe image 1020 formed by sensing the IR light reflected by the object502 (i.e. the object image); numerical references 1024 and 1026respectively refer to the left edge and the right edge of the brightzone 1022; and a numerical reference 1028 refers to a center, a gravitycenter or a mean (or an average) of the bright zone 1022. Numericalreferences 1024, 1026 and 1028 refer to the character information of theobject 502 in the image 1020. In addition, other character informationof the object 502, such as the parameter of area, length width ratio,boundary, color and/or brightness of the object image may also beprocessed by the processing circuit 570 or be preprocessed by the imagesensors 512 and 532. In this embodiment, the character information isobtained by the processing circuit 570.

FIG. 11 shows a schematic diagram of corresponding angles relative toobject positions in an image acquired by the image sensor 512. Asmentioned above, after receiving the image 1010, the processing circuit570 calculates the center, the gravity center or the mean (or average)of the bright zone 1012, i.e. a position of the object 502 in the image1010. Please refer to FIGS. 9, 10 and 11, in order to obtain theincluded angle α1 between the dotted line 582 and the route 902, theimage 1010 may be averagely divided into a plurality of sections, e.g.90 sections. Each section may represent 1 degree angle, and the rightedge of the image 1010 may be defined as 0 degree and the left edge maybe defined as 90 degrees. When the center, the gravity center or themean (or average) of the object falls within the image 1010, the angleα1 corresponding to the position of the object can be obtained. Forexample, 1018A represents that the angle α1 is 45 degrees; 1018Brepresents that the angle al is 30 degrees; and 1018C represents thatthe angle α1 is 75 degrees. If an integral angle can not be obtained, aninterpolation can be used to calculate the exact angle. Similarly, theangle β1 can also be obtained by using similar method.

Please refer to FIG. 9, by using the position of point A and the angleα1 which are already known, a linear equation of the route 902 may beobtained by using point-slope form. Similarly, a linear equation of theroute 904 may also be obtained according to the position of point B andthe angle β1. Therefore, the processing circuit 570 may calculate across point of these two routes and further obtain the position of theobject 502. This kind of calculation method for the object position iscalled intersection of two lines. In addition, the portable opticaltouch system 500 may utilize other methods, e.g. the triangulation, tocalculate the position of the object 502 and since this method has beenbroadly used in conventional optical touch systems, details thereof willnot be repeated herein. Furthermore, according to the description above,a person skilled in the art can realize that the portable optical touchsystem 500 may also be used for multi-touch application.

Furthermore, in addition to the object 502 to be detected, other objectsmay also exist distantly in the field of views of the image sensors 512and 532, and these objects may also reflect IR light to interfere thetouch control of the optical touch system 500. The brightness ofreflected IR light by an object may be used to identify whether anobject image is valid or not. For example, but not limited to, apredetermined brightness threshold or a predetermined brightness rangemay be preset in the processing circuit 570, and the brightness of everypixel in the image acquired by the image sensors 512 and 532 may becompared with the predetermined brightness threshold or range. If thebrightness of a pixel exceeds the predetermined brightness threshold orfalls within the predetermined brightness range, the brightness of thispixel is confirmed to satisfy a predetermined standard. In this way, thebrightness of every pixel will be examined sequentially in order toremove other objects and keep the object 502 to be detected.

It should be mentioned that in an actual design, the IR emitters 518 and538 may be implemented by using at least one IR light emitting diode(LED), and the IR filters 514 and 534 may be implemented by using anIR-pass filter. The wavelength of the IR light emitted by the IR LED maybe about 800 nm to 960 nm, and generally the IR LED emitting the IRlight of about 850 nm wavelength is used. In addition, as the filed ofview of an image sensor is generally 30 to 45 degrees, a number of theoptical lenses adopted in the optical lens sets 516 and 536 may beproperly designed according to the field of view of the image sensor andthe field of view that one optical lens can increase. Although in thisembodiment, the processing circuit 570 is disposed inside the housing5101 of the image sensing module 510 and the communication interface 560is coupled to the housing 5101 of the image sensing module 510, they areonly exemplary rather than limitations to the arrangements of theprocessing circuit 570 and the communication interface 560. In addition,the surface of the object 502 mentioned above may be coated withreflecting material to increase the reflection efficiency thereof.

In addition, the communication interface 560 may also be a wirelesscommunication interface, such as a bluetooth wireless communicationinterface, a wireless universal serial bus (wireless USB) interface oran ultra wide band (UWB) wireless interface. Furthermore, thecommunication interface 560 may use a plurality of wired communicationinterfaces and a plurality of wireless communication interfaces.

According to the above description, it is known that a range of thetouch region 590 may be indefinite theoretically. However, a size of thetouch region 590 may be limited by software. Please refer to FIG. 9again, in the touch region 590 a length of the side denoted by thedotted line 582 is already known, and lengths of the two sides denotedby the dotted lines 584 and 586 are indefinite theoretically. In orderto limit the length of the two sides denoted by the dotted lines 584 and586 to a predetermined length, the processing circuit 570 may definedifferent touch regions according to different applications. Forexample, if the optical touch system 500 is served as a virtual mouse,the size of the touch region 590 in front of the image sensing modules510 and 530 may be defined according to a general size of a physicalmouse familiar to a user, e.g. the touch region may have a size of 15cm×15 cm (i.e. a length of dotted line 582×a length of dotted line 584).Or the processing circuit 570 may define the predetermined length of thedotted lines 584 and 586 in real time according to a relation between asize and a distance of the object image, or the predetermined length maybe defined according to the brightness of reflected light of the objectimage, or the predetermined length of the dotted lines 584 and 586 maybe defined in real time by combining the two methods mentioned above,and the definition method may be built in the software or the firmwareadopted in the processing circuit 570. In this manner, the touch region590 may be a quadrilateral touch region having a predetermined area.

As mentioned above, in the case of the touch region 590 having apredetermined area, the processing circuit 570 may first calculate theposition of the object 502 and then identify whether the object 502 isinside the touch region 590. Only if the object 502 is inside the touchregion 590, the processing circuit 570 will output information of theposition of the object 502 through the communication interface 560. Ofcourse, the processing circuit 570 may also first calculate the positionof the object 502 and transmit the calculated information of theposition of the object 502 through the communication interface 560 tothe electronic device mentioned above to allow the electronic device toidentify whether the object 502 is inside the touch region 590 and todetermine whether to use the calculated information of the position ofthe object.

Second Embodiment

This embodiment is mainly used to illustrate that the portable opticaltouch system 500 may also use the hardware to limit the field of viewsof the image sensors 512 and 532 from infinite to finite as shown inFIG. 12.

FIG. 12 shows another arrangement of internal components of the imagesensing module 510. In FIG. 12, numerical references identical to thoseshown in FIG. 5 refer to the same components. As shown in FIG. 12, thereis a first predetermined included angle θ3 between the image sensingsurface 512A of the image sensor 512 and the bottom surface 5101A of thehousing 5101, and the first predetermined included angle θ3 is smallerthan 90 degrees in this embodiment. In addition, the IR filter 514,optical lens set 516, IR emitter 518 (not shown in FIG. 12) and opticallens 520 (not shown in FIG. 12) are disposed in association with thefirst predetermined included angle θ3; wherein dispositions of the IRemitter 518 and the optical lens 520 have to allow the propagationdirection of the

IR light to be substantially parallel to the actual working surface 802.As the first predetermined included angle θ3 is smaller than 90 degrees,the image sensor 512 has a limited field of view, i.e. a depth of fieldof the image acquired by the image sensor 512 is finite. In otherembodiments, the first predetermined included angle θ3 may also belarger than 90 degrees, and field of views of the image sensors may bedefined in real time according to a relation between a size and adistance of the object image, or according to the brightness ofreflected light of the object image, or by combining the two methodsmentioned above.

Similarly, the image sensor 532, IR filter 534, optical lens set 536, IRemitter 538 and optical lens 540 in the image sensing module 530 mayalso be arranged similar to FIG. 12. Further, there is a secondpredetermined included angle between an image sensing surface of theimage sensor 532 and a bottom surface of the housing 5301, and thesecond predetermined included angle is smaller than 90 degrees in thisembodiment. In other embodiments, the second predetermined includedangle may also be larger than 90 degrees.

Please refer to FIG. 9 again, since the field of views of the imagesensors 512 and 532 become limited, in the touch region 590 lengths ofthe two sides denoted by the dotted lines 584 and 586 may be defined bythe farthest field of view detectable by the image sensors 512 and 532.The farthest field of view detectable by the image sensors may becalculated according to FIG. 13. In FIG. 13, D represents the farthestfield of view that the image sensor 512 can detect (i.e. lengths of thedotted lines 584 and 586), H represents a height of the image sensor512, and θ2 represents an angle. A relation between D, H and θ2 may berepresented by an equation D=H/tan(θ2) shown in FIG. 13, and a sum of θ3(refer to FIGS. 12) and θ2 equals 90 degrees. For example, when H is 5mm and θ2 is 1.91 degrees, D can be calculated from the equationH/tan(θ2) to be 150 mm.

Third Embodiment

This embodiment is mainly used to illustrate that the portable opticaltouch system 500 may use another hardware design to limit the field ofviews of the image sensors 512 and 532 from infinite to finite as shownin FIG. 14.

FIG. 14 shows a modified portable optical touch system 500. In FIG. 14,numerical references identical to those shown in FIG. 5 refer to thesame components. In the optical touch system 500 shown in FIG. 14, avolume of the housing 5101 of the image sensing module 510 is enlarged,and the housing 5101 has a first body 51011 and a second body 51012. Thecommunication interface 560 is coupled to the first body 51011 while theimage sensor 512, IR filter 514, optical lens set 516, IR emitter 518,optical lens 520, processing circuit 570 and transparent part 5102 areall disposed in the second body 51012. The second body 51012 isconfigured to connect to the length-adjustable connecting device 550,and the second body 51012 is rotatable relative to the first body 51011.

As the length-adjustable connecting device 550 is connected to thesecond body 51012 and the housing 5301 of the image sensing module 530is further connected to the length-adjustable connecting device 550,when the second body 51012 is rotated relative to the first body 51011,the length-adjustable connecting device 550 and the image sensing module530 are also rotated by the same angle.

In this manner, when the portable optical touch system 500 is put on orclose to an actual working surface, the field of views of the imagesensors 512 and 532 may be changed from infinite to finite according tothe rotation angle.

Fourth Embodiment

From the teaching of the first embodiment, it is known that as long asthe length-adjustable connecting device 550 of the portable opticaltouch system 500 has enough volume, the image sensing module 510 may nothave the housing 5101, and the image sensor 512, IR filter 514, opticallens set 516, IR emitter 518 and optical lens 520 may be disposed in oneterminal of the length-adjustable connecting device 550. Similarly, theimage sensing module 530 may not have the housing 5301, and the imagesensor 532, IR filter 534, optical lens set 536, IR emitter 538 andoptical lens 540 may be disposed in the other terminal of thelength-adjustable connecting device 550. Of course, the image sensors512 and 532 still need to have partially overlapped field of views suchthat the partially overlapped field of views may be used to define atouch region. As for the communication interface 560 and the processingcircuit 570, they may be disposed at will as long as the processingcircuit 570 is still electrically coupled to the communication interface560, the image sensor 512 and the image sensor 532.

It should be mentioned that in this embodiment, the image sensors 512and 532 may have infinite field of views theoretically.

Fifth Embodiment

From the teachings of the fourth and the second embodiments, it is knownthat in the portable optical touch system 500 of the fourth embodiment,the image sensors 512 and 532 may be designed to rotate about an axis ofthe length-adjustable connecting device 550 by a predetermined angle,and the predetermined angle is smaller than 90 degrees. Of course, theIR filter 514, optical lens set 516, IR emitter 518 and optical lens 520also have to be properly adjusted corresponding to a rotation angle ofthe image sensor 512; and the IR filter 534, optical lens set 536, IRemitter 538 and optical lens 540 also have to be properly adjustedcorresponding to a rotation angle of the image sensor 532. In thismanner, when the portable optical touch system 500 is put on an actualworking surface, the field of views of the image sensors 512 and 532 maybe changed from infinite to finite according to the rotation direction.

Sixth Embodiment

This embodiment is mainly used to illustrate that in the portableoptical touch system adopting an IR emitter, at least one optical lensin every optical lens set is alternatively coated with a plurality ofMgO layers and a plurality of TiO₂ or SiO₂ layers such that the at leastone optical lens can have the function of an IR filter. Accordingly, theoriginal IR filter may not be implemented in this embodiment.

It should be mentioned that, the original IR filter refers to so calledphoto resistor and the material thereof includes organic compound,polymer and plastic.

Seventh Embodiment

This embodiment is mainly used to illustrate that in the portableoptical touch system adopting an IR emitter, each IR emitter may bereplaced by a laser emitting device and every IR filter may not beimplemented. In addition, each optical lens in every optical lens setmay not be coated with the MgO, TiO₂ and SiO₂ layers. It should be notedthat, each optical lens disposed in front of the laser emitting devicehas to be able to convert a point light source emitted by the associatedlaser emitting device to a linear light source to have the laser lightemitted by the associated laser emitting device be able to cover atleast the touch region. In this manner, the laser light emitted by everylaser emitting device may illuminate the object inside the touch region,and every image sensor is able to acquire the image of the objectreflecting the laser light. In other embodiments, the laser emittingdevice may be disposed outside the image sensing module and in thevicinity of the image sensing module to illuminate the object 502 andthe touch region 590. In addition, with proper design, at least onelaser emitting device is implemented and disposed in the vicinity of theimage sensing module 510 and/or the image sensing module 530 toilluminate the object 502 and the touch region 590, and the portableoptical touch system 500 further includes at least one optical lens (oroptical lens set) disposed in front of the at least one laser emittingdevice and configured to convert a point laser light to a linear laserlight to illuminate the object 502 and the touch region 590.

It should be mentioned that, each laser emitting device may beimplemented by using at least one laser diode.

Eighth Embodiment

This embodiment is mainly used to illustrate that in the portableoptical touch system adopting a length-adjustable connecting device, thelength-adjustable connecting device may be replaced by a connectingdevice having a fixed length.

Ninth Embodiment

This embodiment is mainly used to illustrate that in the portableoptical touch system of the present invention the processing circuit maybe designed to be able to further define a function pattern inside thetouch region for implementing a virtual user input device such as amouse, a keyboard, a touchpad or a switch. Taking the portable opticaltouch system of the second embodiment as an example, its processingcircuit may be designed to further define a function pattern having themouse function inside the touch region as shown in FIG. 15.

FIG. 15 shows the function pattern of a mouse in the touch regiondefined by the processing circuit mentioned above. In FIG. 15, theparallelogram formed by connecting lines between points A, B, E and Frefers to the touch region 590 herein, wherein the points A and B arethe positions of the two image sensors in the portable optical touchsystem. In addition, the region L is a virtual left button of a mouse,the region M is a virtual roller of a mouse, and the region R is avirtual right button of a mouse. In this manner, a user may operate byusing the mouse function emulated by this touch region 590.

Tenth Embodiment

This embodiment is mainly used to illustrate that in the portableoptical touch system of the ninth embodiment, a light projector mayfurther be implemented to project the function pattern defined by theprocessing circuit on an actual working surface, such as projecting afunction pattern having the mouse function, keyboard function, etc. Alight source of this light projector may be a visible laser light sourceor a visible IR light source.

Eleventh Embodiment

The first embodiment pointed out that after obtaining the position of anobject, the processing circuit may transmit information of the positionthrough the communication interface to an electronic device. Thisembodiment is mainly used to illustrate that if this electronic devicehas a display screen, e.g. a notebook, the processing circuit in theportable optical touch system of the present invention may be designedto communication with this electronic device though the communicationinterface to correlate the position of the object to a cursor positionon the display screen of this electronic device.

Twelfth Embodiment

This embodiment is mainly used to illustrate that on the housing of theelectronic device mentioned in the eleventh embodiment, a slot mayfurther be formed thereon such that the portable optical touch system ofthe present invention may be disposed in the slot as shown in FIG. 16.FIG. 16 shows a schematic diagram of the portable optical touch systemof the present invention being disposed in a slot of an electronicdevice. The electronic device 1602 shown in FIG. 16 uses a notebook asan example.

Thirteenth Embodiment

From the teaching of the twelfth embodiment, it is known that if theportable optical touch system of the present invention is built in aportable electronic device having a display screen, this electronicdevice may also be called a portable optical touch system. Of course, ina built-in portable optical touch system, a length-adjustable or anunadjustable(fixed) connecting device may not be implemented. Inaddition, the built-in portable optical touch system may adopt an IRemitter or a laser emitting device to illuminate the object in the touchregion.

Fourteenth Embodiment

From the teachings of the above embodiments, it is known that if theobject to be detected can illuminate by itself, e.g. emitting IR lightor laser light, the aforementioned portable optical touch systems maynot adopt an IR emitter or a laser emitting device to illuminate theobject. Of course, the optical lens disposed in front of the IR emitteror laser emitting device and other associated components may not beimplemented.

According to the above embodiments of the portable optical touch systemadopting a connecting device, a basic flow chart of the method fordetecting the object position can be concluded as shown in FIG. 17. FIG.17 shows a flow chart of the method for detecting a position of at leastone object according to an embodiment of the present invention. Themethod may be adapted to a portable optical touch system that includes afirst image sensing module, a second image sensing module, a connectingdevice, a processing circuit and a communication interface; wherein afield of view of the first image sensing module and a field of view ofthe second image sensing module are partially overlapped and thepartially overlapped field of views is for defining a touch region. Theconnecting device is configured to adjust or fix a distance between thefirst and second image sensing modules. The method includes the stepsof: acquiring images of the object in the touch region by using thefirst and second image sensing modules (Step S1702); calculating theposition of the object by using the processing circuit according to theimages of the object acquired by the first and second image sensingmodules (Step 1704); and outputting information of the position of theobject through the communication interface (Step 1706); wherein theprocessing circuit may calculate the position of the object by usingtriangulation or intersection of two lines.

According to the above embodiments, it is known that the portableoptical touch system of the present invention may replace the currentuser input interfaces such as a mouse, a keyboard, a touchpad and etc.And the portable optical touch system of the present invention iscompact, easy for carry, disposable at will and low cost. In addition,the portable optical touch system of the present invention will not belimited to a smooth working surface as the conventional mouse, and willnot be limited by requiring a physical touch region as the resistive orcapacitive touch panel. According to the above embodiments, it is alsoknown that the portable optical touch system of the present inventionmay be integrated with or communicate with an electronic device having adisplay screen, is able to control the motion of a cursor shown on thedisplay screen, and is even able to realize all functions achievable bycurrent commercial touch screens such as single point control, multiplecontrol and etc. It should be mentioned that, the technology usingoptical detection of an object is also called the optical couplingtechnology, i.e. optical signals reflected by an object is detected byat least one image sensor, and the optical signals are converted intoelectric signals, and the correlation of the electric signals obtainedby the image sensor will be processed at last so as to obtain thecharacter information of the object.

As mentioned above, the present invention mainly adopts two imagesensing modules and a processing circuit to construct a portable opticaltouch system. In an actual design, the two image sensing modules havepartially overlapped field of views and the partially overlapped fieldof views is for defining a touch region. In this manner, when there isan object (e.g. a finger or a pen-like object) inside the touch region,the processing circuit may calculate a position of the object accordingto images of the object acquired the two image sensing modules. In afurther design, the two image sensing modules may emit IR light or laserlight to illuminate the object so as to acquire the images of the objectreflecting the IR light or the laser light whereby the processingcircuit is able to calculate the position of the object according tothese acquired images.

In one aspect, the term “coupled” or the like may refer to beingdirectly coupled. In another aspect, the term “coupled” or the like mayrefer to being indirectly coupled.

Various items may be arranged differently (e.g., arranged in a differentcombination, or implemented in a different way) all without departingfrom the scope of the subject technology. In one aspect of thedisclosure, the elements recited in the accompanying claims may beperformed by one or more modules or sub-modules.

It is understood that the specific combination disclosed is anillustration of exemplary approaches. Based upon design preferences, itis understood that any combination of the modules or elementsaforementioned may be rearranged.

The disclosure is provided to enable any person skilled in the art topractice the various aspects described herein. The disclosure providesvarious examples of the subject technology, and the subject technologyis not limited to these examples.

Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects.

Although the invention has been explained in relation to its preferredembodiment, it is not used to limit the invention. It is to beunderstood that many other possible modifications and variations can bemade by those skilled in the art without departing from the spirit andscope of the invention as hereinafter claimed.

What is claimed is:
 1. A portable optical touch system, comprising: afirst image sensing module comprises a first housing and a first imagesensor disposed in the first housing, wherein a first predeterminedincluded angle is formed between an image sensing surface of the firstimage sensor and a bottom surface of the first housing; a second imagesensing module comprises a second housing and a second image sensordisposed in the second housing, wherein a second predetermined includedangle is formed between an image sensing surface of the second imagesensor and a bottom surface of the second housing, and the first andsecond predetermined included angles are equal to or smaller than 90degrees, wherein a field of view of the first image sensing module and afield of view of the second image sensing module are partiallyoverlapped and the partially overlapped field of views is for defining atouch region; a length-adjustable connecting device connecting the firstimage sensing module and the second image sensing module, wherein thelength-adjustable connecting device adjust a distance between the firstimage sensing module and the second image sensing module; acommunication interface; and a processing circuit, coupled to the firstand the second image sensing module for calculating a position of anobject in the touch region according to images of the object acquired bythe first image sensing module and the second image sensing module, andfor outputting information of the position through the communicationinterface.
 2. The portable optical touch system as claimed in claim 1,wherein the first predetermined included angle is equal to the secondpredetermined included angle.
 3. The portable optical touch system asclaimed in claim 1, wherein the first housing comprises a first body anda second body configured to connect to the length-adjustable connectingdevice, and the second body rotates relative to the first body.
 4. Theportable optical touch system as claimed in claim 1, wherein the firsthousing and the second housing are configured to connect the connectingdevice and respectively comprise a first transparent part and a secondtransparent part such that the first image sensor and the second imagesensor respectively acquire images through the first transparent partand the second transparent part.
 5. The portable optical touch system asclaimed in claim 4, wherein the communication interface is coupled tothe first body, and the first transparent part is disposed in the secondbody.
 6. The portable optical touch system as claimed in claim 1,wherein the each image sensing module further comprises an IR emitterand an IR filter allowing only IR light to pass through; the IR emitteris configured to emit the IR light to illuminate the object; and theeach image sensor acquires the images of the object through theassociated IR filter.
 7. The portable optical touch system as claimed inclaim 1, wherein the each image sensing module further comprises an IRfilter allowing only IR light to pass through; the portable opticaltouch system further comprises at least one IR emitter; the at least oneIR emitter is configured to emit the IR light to illuminate the object;and the each image sensor acquires the images of the object through theassociated IR filter.
 8. The portable optical touch system as claimed inclaim 1, wherein the each image sensing module further comprises an IRemitter and an optical lens set; the IR emitter is configured to emit IRlight to illuminate the object; at least one optical lens in the opticallens set is alternatively coated with a plurality of MgO layers and aplurality of TiO₂ or SiO₂ layers; and the each image sensor acquires theimages of the object through the associated optical lens set.
 9. Theportable optical touch system as claimed in claim 8, wherein the eachoptical lens set is configured to broaden the field of view of theassociated image sensor to at least 90 degrees.
 10. The portable opticaltouch system as claimed in claim 1, wherein the each image sensingmodule further comprises a laser emitting device and an optical lens;the laser emitting device is configured to emit a point laser light tobe converted to a linear laser light by the optical lens to illuminatethe object in the touch region; and the each image sensor is configuredto acquire the images of the object.
 11. The portable optical touchsystem as claimed in claim 1, wherein the processing circuit furtherdefines a function pattern in the touch region to be used as a virtualuser input device, wherein the virtual user input device has functionsof a mouse, a keyboard, a touchpad or a switch.
 12. The portable opticaltouch system as claimed in claim 1, wherein the communication interfaceoutputs the information of the position of the object to an electronicdevice comprising a display screen, and the processing circuitcommunicates with the electronic device through the communicationinterface to correlate the position of the object in the touch regionwith a position shown on the display screen.
 13. The portable opticaltouch system as claimed in claim 1, further comprising a light projectorconfigured to project a function pattern on an actual working surfacecorresponding to the touch region such that the processing circuitfurther defines the function pattern in the touch region to be used as avirtual user input device, and the virtual user input device hasfunctions of a mouse, a keyboard, a touchpad or a switch.
 14. A portableoptical touch system, comprising: a first image sensing module comprisesa first housing and a first image sensor disposed in the first housing;a second image sensing module comprises a second housing and a secondimage sensor disposed in the second housing, wherein a field of view ofthe first image sensing module and a field of view of the second imagesensing module are partially overlapped and the partially overlappedfield of views is for defining a touch region; a length-adjustableconnecting device connecting the first image sensing module and thesecond image sensing module, wherein the length-adjustable connectingdevice adjust a distance between the first image sensing module and thesecond image sensing module; a communication interface; and a processingcircuit, coupled to the first and the second image sensing module, forcalculating a position of an object in the touch region according toimages of the object acquired by the first image sensing module and thesecond image sensing module, and for outputting information of theposition through the communication interface; wherein the first housingcomprise a first body and a second body, the second body is configuredto connect to the length-adjustable connecting device, and the secondbody rotates relative to the first body to form a first predeterminedincluded angle between an image sensing surface of the first imagesensor and a bottom surface of the first housing, and a secondpredetermined included angle between an image sensing surface of thesecond image sensor and a bottom surface of the second housing.
 15. Theportable optical touch system as claimed in claim 14, further comprisesan IR device for defining the touch region having a predetermined widthand a predetermined length.
 16. The portable optical touch system asclaimed in claim 14, wherein the predetermined width of the touch regionis determined by the distance between the first image sensing module andthe second image sensing module, and the predetermined length isdetermined by the first predetermined included angle and the secondpredetermined included angle.
 17. The portable optical touch system asclaimed in claim 14, wherein the first housing and the second housingare configured to connect the length-adjustable connecting device andrespectively comprise a first transparent part and a second transparentpart such that the first image sensor and the second image sensorrespectively acquire images through the first transparent part and thesecond transparent part; and the first image sensor and the second imagesensor have the partially overlapped field of views.
 18. The portableoptical touch system as claimed in claim 17, wherein the communicationinterface is coupled to the first body, and the first transparent partis disposed in the second body.
 19. The portable optical touch system asclaimed in claim 14, wherein the each image sensing module furthercomprises an IR emitter and an IR filter allowing only IR light to passthrough; the IR emitter is configured to emit the IR light to illuminatethe object; and the each image sensor acquires the images of the objectthrough the associated IR filter.
 20. The portable optical touch systemas claimed in claim 14, wherein the each image sensing module furthercomprises an IR filter allowing only IR light to pass through; theportable optical touch system further comprises at least one IR emitter;the at least one IR emitter is configured to emit the IR light toilluminate the object; and the each image sensor acquires the images ofthe object through the associated IR filter.
 21. The portable opticaltouch system as claimed in claim 14, wherein the each image sensingmodule further comprises an IR emitter and an optical lens set; the IRemitter is configured to emit IR light to illuminate the object; atleast one optical lens in the optical lens set is alternatively coatedwith a plurality of MgO layers and a plurality of TiO₂ or SiO₂ layers;and the each image sensor acquires the images of the object through theassociated optical lens set.
 22. The portable optical touch system asclaimed in claim 21, wherein the each optical lens set is configured tobroaden the field of view of the associated image sensor to at least 90degrees.
 23. The portable optical touch system as claimed in claim 14,wherein the each image sensing module further comprises a laser emittingdevice and an optical lens; the laser emitting device is configured toemit a point laser light to be converted to a linear laser light by theoptical lens to illuminate the object in the touch region; and the eachimage sensor is configured to acquire the images of the object.
 24. Theportable optical touch system as claimed in claim 14, wherein theprocessing circuit further defines a function pattern in the touchregion to be used as a virtual user input device, wherein the virtualuser input device has functions of a mouse, a keyboard, a touchpad or aswitch.
 25. The portable optical touch system as claimed in claim 14,wherein the communication interface outputs the information of theposition of the object to an electronic device comprising a displayscreen, and the processing circuit communicates with the electronicdevice through the communication interface to correlate the position ofthe object in the touch region with a position shown on the displayscreen.
 26. The portable optical touch system as claimed in claim 14,further comprising a light projector configured to project a functionpattern on an actual working surface corresponding to the touch regionsuch that the processing circuit further defines the function pattern inthe touch region to be used as a virtual user input device, and thevirtual user input device has functions of a mouse, a keyboard, atouchpad or a switch.